For behind the scenes pictures, stories and special contests, follow us on Facebook!

Monday Morning Physics Fun – Eddy Currents Demonstrated

By Andrew Liszewski

I know for a lot of people, Monday morning isn’t exactly the time when their brain is functioning at full capacity. But I thought this video demonstrating Eddy currents was certainly worth sharing. The demonstrator is simply dropping a small stack of neodymium magnets down a thick-walled section of copper pipe. And even though the magnets aren’t attracted to the pipe, their descent is still slowed dramatically on the way down. Either that, or this is a brilliant hoax, and that pipe is actually a mile long.

And since I’m one of those persons whose brain doesn’t fully kick in until late Tuesday, I’m including Wikipedia’s description of Eddy currents if you’re curious as to what’s supposedly going on here:

Eddy currents (also called Foucault currents[1]) are currents induced in conductors, when a conductor is exposed to a changing magnetic field due to relative motion of the field source and conductor; or due to variations of the field with time. This can cause a circulating flow of electrons, or a current, within the body of the conductor. These circulating eddies of current have inductance and thus induce magnetic fields. These fields can cause repulsive, attractive,[2] propulsion and drag effects.

[ YouTube – Copper Pipe Magnet ] & [ Wikipedia – Eddy Current ]